ATM Unipin Voucher

I purchased unipin voucher for the value of R500 at a ATM machine but the voucher never came out ..the slip showed an error message but the money was deducted from my account..I called the bank on the 3rd of September requesting my refund I was told that the matter has been escalated..I phone last week did not get favourable response..I phoned again on Saturday I was told that the office that deals with ATM matters is closed I phoned again on the 16th i was told that the case is closed..I don't understand how because I have the reference number how can it be closed when no one called me..

Nedbank is the worst in paying out their clients..